On basal slip and basal twinning in sapphire ({alpha}-Al{sub 2}O{sub 3}). 1: Basal slip revisited
- Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering
The motion of partial dislocations in sapphire ({alpha}-Al{sub 2}O{sub 3}) is analyzed. Crystallographic arguments suggest that the basal slip plane should be a plane passing through the normally-vacant octahedral sites defined by the anion sublattice. This definition of the basal slip plane implies that half of the cations lying between two adjacent anion layers are above and the other half are below the slip plane. The stacking faults that would be created by the motion of a dissociated basal dislocation differs in structure and energy, depending on whether the partial is leading or trailing. Thus, the motion of a partial in its favorable (lower energy) direction creates a stacking fault with a stacking /sequence in which the cations are in a localized twin symmetry, whereas the motion of a partial in its unfavorable (higher energy) direction is ``forbidden``.
- DOE Contract Number:
- FG02-93ER45496
- OSTI ID:
- 247965
- Journal Information:
- Acta Materialia, Vol. 44, Issue 5; Other Information: PBD: May 1996
- Country of Publication:
- United States
- Language:
- English
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